Computer aided modelling of a virtual reality is the task of creating a model of a physical object, manipulating the model, and otherwise handling a model of a physical object in a computer system.
From a first point of view, modelling of a virtual reality is an interesting topic in that it makes it possible to visualise ideas before they are actually implemented in the real world. If the virtual reality model is sufficiently easy to modify, much time can be saved in the process of developing and refining a physical object compared to a situation where the same process should have been carried out in the real world. A simple task of painting an object in the real world may easily take several hours, whereas the computer can apply a new colour to a model within milliseconds or seconds.
From a second point of view, modelling of a virtual reality is interesting in that it makes it possible to create a model of an object that exists in the real world and, via a computer, to visualise and manipulate the model. Thus the model of the object can be stored for different purposes, e.g. for advanced documentation purposes.
Although there exists a huge amount of possible applications for computer aided virtual reality modelling, a special application is to use virtual reality modelling for entertainment or education.
Various types of modelling concepts of physical construction toy sets are known as such. Especially, concepts using modular or semi-modular concepts are very popular. Typically, these concepts provide a set of pre-manufactured elements that can be interconnected with each other in some predetermined way according to modules of the pre-manufactured elements. An example of such a construction toy set is a set of plastic toy building elements available under the name LEGO.
When manipulating representations of three-dimensional (3D) objects or scenes on a computer it is a general problem that a positioning, selection or movement of an object in 3D is performed by means of an input device operating in two dimensions, e.g. the two-dimensional (2D) movements of a computer mouse on a mouse pad. Furthermore, the display area of a computer is two-dimensional as well. In particular, every selected position on the 2D display area of the computer screen corresponds to a plurality of positions in the 3D space having a projection onto the 2D display area corresponding to the selected 2D position. It is a problem to determine one of the positions that is likely to correspond to the user's intention.
Even though considerable efforts have been made to develop computer interface devices that are more suitable for manipulating objects in a 3D computer-graphics, such tools are not yet widely used, in particular not in connection with computer systems used for home entertainment, education, etc.
Known construction games where virtual building blocks are positioned are typically restricted in terms of the degrees of freedom of the movements and rotations of the objects or of the ways of connecting them with other objects.
U.S. Pat. No. 6,426,745 describes a method of manipulating a 3D graphics object with a mouse where a movement in 3D is performed by restricting the movement to one plane or one direction at a time, thereby performing the 3D movement as a sequence of restricted movements, e.g. as a sequence of movements in the x-direction, than the y-direction and finally in the z-direction of a 3D coordinate system.
It is a problem of the above prior art systems that the placement of building blocks in a 3D scene and their connection to a 3D structure with conventional user interfaces is a cumbersome process which requires a high level of skill and training. In particular in the context of entertainment and education of children and teenagers this is a problem, since children often have not yet developed sufficient motoric skills or the required patience to perform a lengthy manipulation process. Consequently, they may very soon loose interest in a virtual construction game.